The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/29a97102541a399d23f9975973a6b7813c0aaa37

commit 29a97102541a399d23f9975973a6b7813c0aaa37
Author: juncai <juncai@chromium.org>
Date: Fri Oct 14 20:12:11 2016

Change signal strength image using grey color

This CL changes the signal strength image using grey color, sinice grey
is the default color for Chrome icons.

BUG= 652804 

Review-Url: https://codereview.chromium.org/2396623002
Cr-Commit-Position: refs/heads/master@{#425446}

[modify] https://crrev.com/29a97102541a399d23f9975973a6b7813c0aaa37/ui/resources/default_100_percent/common/signal_0_bar.png
[modify] https://crrev.com/29a97102541a399d23f9975973a6b7813c0aaa37/ui/resources/default_100_percent/common/signal_1_bar.png
[modify] https://crrev.com/29a97102541a399d23f9975973a6b7813c0aaa37/ui/resources/default_100_percent/common/signal_2_bar.png
[modify] https://crrev.com/29a97102541a399d23f9975973a6b7813c0aaa37/ui/resources/default_100_percent/common/signal_3_bar.png
[modify] https://crrev.com/29a97102541a399d23f9975973a6b7813c0aaa37/ui/resources/default_100_percent/common/signal_4_bar.png
[modify] https://crrev.com/29a97102541a399d23f9975973a6b7813c0aaa37/ui/resources/default_200_percent/common/signal_0_bar.png
[modify] https://crrev.com/29a97102541a399d23f9975973a6b7813c0aaa37/ui/resources/default_200_percent/common/signal_1_bar.png
[modify] https://crrev.com/29a97102541a399d23f9975973a6b7813c0aaa37/ui/resources/default_200_percent/common/signal_2_bar.png
[modify] https://crrev.com/29a97102541a399d23f9975973a6b7813c0aaa37/ui/resources/default_200_percent/common/signal_3_bar.png
[modify] https://crrev.com/29a97102541a399d23f9975973a6b7813c0aaa37/ui/resources/default_200_percent/common/signal_4_bar.png